A new operation framework of demand-side energy storage system cooperated with power system

Energy storage systems have increasingly been expected as a means of load leveling of the annual load factor in Japan. The demand-side energy storage system has the effects for not only improving load factor, but also for black out compensation or voltage sags. So it is expected to wide spread in the future. Then the authors proposed a method that the energy storage systems at customer side are used for a congestion relief on transmission networks. Consequently it is cleared in this paper that which kind of customers has the effect of relieving transmission line congestion. First of all, the authors determine the optimal configuration of energy system including energy storage system. By using an optimal power flow with unit commitment as an evaluation index of electric utility, this paper evaluates the possibility that gives cost merit to both the electric utility and the customer from economic point of view.